Request: Detect unlikely combinations of characters

[glocalglocal]

It would be great if this plugin could detect unlikely combinations of characters as likely spelling mistakes. Eg

• multiple spaces between words, between a word and a punctuation mark, or a word and a symbol, etc eg word word, word ., 12.3 %, word) .
• multiple or impossible combinations of punctuation marks eg word ,., word.., word1,, word2
• repeated word eg word word
• redundant spaces at the end of a line.
• double or triple minus instead of n-dash and m-dash

Strictly speaking, this could be the job for a linter or a grammar checker, but I couldn't find another plugin doing any of this. It may not be difficult to add this functionality and it would make a big difference.